1: 3-iodo-1-(phenylsulfonyl)-1H-indole With i -Pr2Zn; Li(acac) in 1-methyl-pyrrolidin-2-one T=20°C; 12 h; 2: allyl bromide in tetrahydrofuran T=20°C;

1: sec.-butyllithium / tetrahydrofuran / 20 h / -70 °C 2: osmium(VIII) oxide; water; 4-methylmorpholine N-oxide / acetone; tert-butyl alcohol / 18 h 3: sodium chlorite; sodium dihydrogen phosphate monohydrate / tetrahydrofuran; 2-methyl-but-2-ene; water; tert-butyl alcohol / 1.5 h / 0 °C 4: Reflux View Scheme